I have a feeling this is going to divide Brookmyre's fans (again).
It's a full blooded science fiction story, akin to last book but two Pandaemonium rather than the more recent "straight" crime fiction. Indeed, there's a case for saying that in narrative terms, this book picks up almost where Pandaemonium left off - with a character flung unexpectedly form this world into another reality, albeit that of a violent video game rather than a violent parallel universe.
So begins a breakneck narrative as Ross, a browbeaten Scottish techie with a Dilbertish outlook, tries to find out what has happened and how he can get back to familiar, damp Stirling and his girlfriend Carol. He soon discovers that there's more going on than a simple brain scanner accident, and that events inside and outside the game are threatening its reality: a Corruption is spreading...
It is an exciting story, interspersing chases, combat, philosophy (are we all in a simulation?) and ethical debate (if the simulated inhabitants of a game are sophisticated enough, does that make them human? If so, what rights should they have?) The plot is intricate and, for the first half of the book, pretty baffling, turning on a few unexpected reveals which it would spoil to say much more about. But everything does become clear in the end (perhaps there is a bit too much exposition in the final 20 pages or so) and - no surprise - it turns out to have been very deftly put together.
I enjoyed this book. Brookmyre shows his knowledge of 80s and 90s video games, moving Ross through a succession of different game milieux from first person shooters to platform games to a warped version of The Sims - yet as a non-gamer I never felt left out of baffled. (If I were "Daily Mail" reader, I might have felt got at by one section...)
Philosophically, it felt as though he was joining in an ongoing discussion among Scottish based SF writers about the "simulation hypothesis" and its consequences, coming after books such as Ken MacLeod's The Restoration Game and Charles Stross's The Rapture of the Nerds.
In a postscript, Brookmyre hopes readers will find this venture into SF proper worthwhile - so do I, because it would be a shame if there were no more like this.